Duolingo and many other apps avoid the hardest and most essential skill: translating from your language to the other.

It's often easy to guess what words mean especially with the help of cognates and other similarities between languages. 99% of Duolingo mobile is like this. Even when you see words in your language first, your task is to tap the presented foreigin words in order.

You'll never learn to speak this way. The best way is to flip the order:

    The language is difficult -> La lengua es difícil.

But that's a slog by comparison. The dopamine rush isn't there, which I guess is why no one does this[0].

I actually wrote a script to build Anki decks from Duolingo and Busuu[2] which did this. The front front is a short sentence. The back is a transliteration and translation. Then I discovered Mango Languages (free through many US public libraries) that's the same with great audio and a pretty good flash card system.

I used that strategy 2 hours a day for two months, and I learned enough Italian to argue with a cab driver whose meter "non funziona."

[0]: In Duolingo's defense, the desktop version isn't a tap fest, but there's not enough opportunities to

[1]: https://mangolanguages.com (not sure why no one knows about this)

[2]: https://busuu.com (probably the best for grammar)

[3]: https://memrise.com (very, very good AI text convos with corrections provided and mixed language support)